In semiconductor devices such as a DRAM (Dynamic Random Access Memory), an input circuit that amplifies an input signal with a small amplitude and transmits the amplified signal is employed as a passive circuit for receiving the input signal. Therefore, the input circuit consumes electric power even in a standby state when no input signal is received.
Since data width in semiconductor devices has increased in recent years, many input circuits must be provided on the semiconductor devices and power consumption in the input circuits has increased accordingly. Therefore, it is important to reduce standby electric power consumed in the input circuits.
For example, Patent Document 1 describes a technology in which leak current is reduced by activating an input circuit in accordance with a write command.
[Patent Document 1]
    JP Patent Kokai Publication No. JP-P2008-034098A[Patent Document 2]    JP Patent Kokai Publication No. JP-H11-297950A which corresponds to U.S. Pat. No. 6,195,305B1